They are fun but I don't have the patience. I've played Grim Fandango and some of the Myst games, and more recently those "escape the room" flash games, but never without a walkthrough >_<
But yeah, I saw many tweets about this. I don't know how it begun, but at some point they caught the attention of the media (i believe rock, paper, shotgun said something about it) and it got really popular really fast